I do quite a lot of invertebrate-hunting in all sorts of habitats - grasslands, heathlands, woodlands, coastal areas and so on. Of these, one is particularly tricky - woodland. At ground level it's fine, but I can't help but wonder what's up in the canopy that I can't get at - certainly there's a lot of recent research into canopy ecology around the world (e.g. here) following realisation of its importance alongside some technical advances aiding the research work itself. On a large scale and/or with lots of funding, there are various options - smoking whole trees, building canopy walkways, laying flexible platforms across the treetops, and so on. On a smaller and cheaper scale, there is the option of hoisting flight interception traps into treetops and leaving them to see what falls in before returning to collect the catch. This is something I can do, but a lot of my surveys involve a limited number of visits quite widely separated. This means that traps would have to be left for too long and might suffer from interference from members of the public (unless tied off further up the trees, but that means climbing). So, I got to thinking about how to sample the canopy whilst actually on site and without having to get roped and harnessed.
This meant being able to get a sampling device in and out of the canopy at will, and that the device had to be sufficiently portable to carry by hand from the nearest access point (which can be some distance away). Although tempted by something involving a remote-control helicopter, this seemed fraught with dangers of both cost and getting it stuck up a tree. Nope, that idea was quickly scrapped in favour of something else - a lightweight telescopic pole with a canopy sampler on the end. So, how does that work..?
First, get a series of aluminium poles and cut/fit them as follows:
|Short section riveted into large section|
|Wing-nut fixing in situ|
|Hooked end on pole four. A wire hangs from the bend with one or more loops (to adjust the height of the sampler) at the end. This could equally be strong cord or any other suitable material.|
|Sampler consisting of bag, cone, strings and carabiner modelled by our washing line...|
|The sampler in action, modestly extended, and modelled lovingly by me in our back garden...|